Interview with the founder of Starknet: Looking up at the stars while keeping our feet on the ground.

At the recent EDCON conference in Montenegro, ZK became the hottest topic. From the 19th to the 23rd, during the 5-day event, both individual speeches and panel discussions revolved around terms such as ZK Rollup, zkEVM, and ZKML. In the eyes of the "Ethereum core circle," ZK has become the ultimate new narrative that can rival the 2019 DeFi innovation and trigger the next industry boom.

For a long time, technology implementation has been the main challenge faced by ZK, which has always been seen as the "future solution" in most people's minds. However, this year, even before the Arbitrum ecosystem became popular, ZK Rollups, as a technological alternative, have already knocked on the door. The most obvious feeling this year is that there are suddenly many "ZK projects" of all kinds. Developers have started to FOMO ZK technology, including ZK transfers, ZK identities, and ZK board games. As long as it is related to privacy, the project name will definitely have the word "ZK". This prosperous scene is of course due to the concentrated efforts of ZK Rollups such as Starknet and zkSync, as well as zkEVM projects such as Scroll and Polygon. Behind these pillars is a big Israeli man named Eli Ben-Ssason.

Eli is one of the earliest researchers who combined ZK technology with encryption technology. He is the founder of Zcash and StarkWare, and also the creator of zk-STARK. The technology standard that follows is the important cornerstone of today's Starknet and the entire ZK encryption track. BlockBeats met this legendary figure during the EDCON in Montenegro and in a conversation that lasted nearly an hour, Eli showed strong technical confidence. He revealed to BlockBeats his views on the STARK, SNARK, and Rollup tracks, as well as his expectations for the Starknet ecosystem.

About Optimistic Fraud Proofs, zk-STARKs, and SNARKs

Many people know Eli as the co-founder of StarkWare, but few know that he is also the creator of the zk-SNARK technology standard. Even before Ethereum, Eli began combining ZK technology to solve the scalability issues of blockchain and had in-depth discussions with Vitalik, who was then still an author for Bitcoin Magazine. StarkWare is also one of the few projects in which Vitalik has invested.

Eli Ben-Sasson spoke at the StarkWare Sessions 2023 conference, image source from StarkWare

As a technology-driven entrepreneur, Eli has absolute confidence in ZK technology and its underlying mathematical principles. So how does he view "ZK rival" Optimistic Rollup? What are his thoughts on the future of zk-STARK and zk-SNARK?

BlockBeats: Hello Eli, first of all, please briefly introduce to the readers why you entered the cryptocurrency field and why you founded Zcash and StarkWare?

Eli: I used to be a computer science professor, conducting research in theoretical computer science. People in mainland China may have heard of Yao Qizhi from Tsinghua University, who is an important promoter of theoretical computer science, a Turing Award winner, and the inventor of secure multi-party computation. I entered this research field many years after him.

In 2008, I started researching zero-knowledge proofs (ZKP). In May 2013, ten years ago, I attended the Bitcoin conference in San Jose and realized that the blockchain field was the best application scenario for my theoretical research and mathematics. I was very sure that I was the first person to realize that the proof of general computation and blockchain could be combined very well. Ethereum had not yet appeared ten years ago. When I first met Vitalik, he was not yet the founder of Ethereum, but a content author for Bitcoin Magazine. We discussed many issues related to proofs, validity proofs, and zero-knowledge proofs.

One of my early co-authored papers was called "Zerocash: Decentralized Anonymous Payments from Bitcoin", which discussed how to use zero-knowledge proofs to protect payments on Bitcoin. This later became the Zcash project, and we have been developing this technology ever since. Around 2018, we proposed a better technological improvement called STARK, which helps to scale Ethereum or general blockchains. In 2018, we co-founded StarkWare, with founders including myself, Uri Kolodny, Alessandro Chiesa, and Michael Riabzev. Today, it is widely believed that our proof of validity is the best way to scale Ethereum.

BlockBeats: You mentioned that you had early contact with Vitalik, and I remember he started investing and supporting StarkWare very early on.

Eli: Yes, Vitalik is one of the early investors in StarkWare. This is one of his few investments to date, and we are very proud of it.

I remember Vitalik becoming a core investor around autumn 2018. We attended a meeting together, which seemed to be organized by Tsinghua University, but it was definitely in Shenzhen. I remember us walking in a very beautiful seafood market, discussing things like StarkWare, his investments, and a bunch of other things. So the details of this decision were reached in China.

BlockBeats: How did you see that blockchain would definitely have scalability issues, given that you started considering the use of ZK proofs as a scaling solution before Ethereum?

Eli: I believe that readers in the Chinese community are familiar with Alipay and WeChat Pay, whose transaction speed may have reached one million transactions per second. Now, blockchain needs to handle NFTs, games, voting, elections, and governance. To make all of these happen, the current technology is not good enough. In Bitcoin and Ethereum, there are about 10 to 20 transactions per second. This requires other technologies that do not reduce the security of the blockchain but can expand the scope or reach of the blockchain. This is what Starknet does.

BlockBeats: Professor Ed Felten, founder of Arbitrum, also began addressing scalability issues around 2014, but he decisively chose interactive fraud proof, which later became widely regarded as the more feasible optimistic fraud proof. Why did you decide to use ZK as the solution from the beginning?

Eli: This is a better technology and it is indeed effective. In fact, everyone in the Ethereum core team knows that Optimistic Rollups has not activated their core technology. Neither Arbitrum nor Optimistic have fraud proofs. The reason they haven't been launched is because they simply don't work.

On the contrary, we have never submitted a state update without a valid STARK proof. Even if our system performance reaches 10 times that of Ethereum, we only use less than 1% of Ethereum resources. Optimistic Rollups is a good idea, but it doesn't work, and because it doesn't work, it hasn't been activated. There is a big difference between something that should work but doesn't, and another technology that does work and can be proven.

BlockBeats: Although Vitalik invested in StarkWare, he later supported Optimism. There seems to be an increasingly strong consensus in the cryptocurrency industry that scalability issues should first be addressed with Optimistic solutions before turning to ZK, as ZKP or ZK Rollup are much more difficult to implement technically than Optimistic. What do you think about this?

Eli: I like the Optimism team, they are outstanding members of the community, but their technology is not good. It's like why can't we attach feathers to people and have them flap their wings to build airplanes? It's more meaningful, that's why Leonardo da Vinci painted people with wings. But it doesn't work in math and economics. I really appreciate and admire their intelligence and truly great community members, but we can't change the fact that it's a technology that can't work well in the long run.

BlockBeats: However, as an ordinary user, Optimism and Arbitrum are indeed practical solutions currently available.

Eli: Of course, but it is important to realize that your asset security relies on trusting a single operator, which can work very effectively. There is another possibility that works well. You can bridge your assets to any computer you trust very much. It can be a centralized exchange or anything similar, and then you will get amazing TPS throughput, but you are entrusting all your funds to the computer controlled by that person. If it fails, drops out, or behaves maliciously, all your funds will disappear.

Arbitrum, Optimism, and Binance share the same security assumptions. Binance is a good product for users, and may even be better than Arbitrum, but it is important for users not to be fooled into thinking they have a higher level of security when transferring assets. If someone says they don't know how to use Binance because it is controlled by a centralized process, and they want to go decentralized by putting their assets on Arbitrum or Optimism, it is actually the same thing.

BlockBeats: So when users use Optimism or Arbitrum, are they actually using a centralized trading platform?

Eli: They are using a centralized system, and even worse, it is based on a codebase that was not originally designed to be operated by a single operator. So I think the legal protection it provides you is not as good as Binance's.

BlockBeats: Speaking of ZKP, you have created zk-STARK outside of the widely recognized zk-SNARK. Why set two different technical standards for ZK technology? And why did StarkWare ultimately choose zk-STARK?

Eli: SNARKs technology, Groth-16 type pre-processing SNARKs that uses elliptic curves, can be prepared for production earlier, but I think it is a less efficient and secure technology. It's like having a technology that isn't that good, but it appears first, like how the steam engine isn't as good as the gasoline engine, but it appeared first. I think it's a bit similar to this situation.

As for why to choose zk-STARK, it is an unquestionable choice. It has the most secure and future-proof underlying technology, relying on battle-tested mathematics and encryption techniques. It is worth mentioning that it is post-quantum secure, which other systems cannot achieve. It has the fastest and most efficient proofs, and because of these, it has reached the highest level among all proof technologies.

zk-STARK and zk-SNARK technology detail comparison chart, image source from Horizon Academy

BlockBeats: Many ZK Rollup and zkEVM projects currently use zk-SNARK. What is your opinion on the future of zk-SNARK?

Eli: I think it will be gradually phased out. It may be left for personal shielded transactions, and in some cases, users may not care about the inefficiency of proof time. And there are indeed very short proofs, about 200 bytes or so. So they may have some use in the privacy field, for personal shielded transactions, but once they reach larger throughput, that's all they can do. All projects in the Polygon system are using STARKs, from Hermez, Miden to Polygon Zero, and so on. Some projects are currently using SNARKs, but they will eventually switch to STARKs. So, now the largest number of blockchain validity proof projects are using STARKs.

About Starknet, Cairo, and zkEVM

Many people find it difficult to understand that as an Ethereum L2, Starknet itself is not compatible with Ethereum EVM, and developers need to use the new language called Cairo for contract development. This seems to make Starknet lose many advantages of EVM-compatible L1 and Ethereum-equivalent L2, which is to minimize development costs and quickly launch the ecosystem in a short period of time. However, in Eli's view, these issues become less important in the face of the huge potential brought by Cairo. More importantly, the Starknet ecosystem has its own solutions to this.

BlockBeats: Why did StarkWare create two different projects, StarkEx and Starknet? Why not combine them?

Eli: StarkEx and Starknet serve two different purposes. When you're talking about a very specific type of high-throughput transaction, such as minting and trading NFTs, you can get better performance and throughput from a system built specifically for this purpose, which is StarkEx. We started with a very specific use case and tested the entire technology in practice, and we're very proud of it.

Starknet, on the other hand, undergoes a more complex construction process, so it is natural that it will appear later and serves a different purpose. It allows for general computation, similar to Ethereum, but this general computation means that its performance will not be as good as specific performance for a particular use case. Therefore, this is a trade-off between generality and efficiency.

BlockBeats: So for the StarkWare team, achieving high transaction TPS in specific application scenarios is very important?

Eli: Yes, it is very important for us to achieve this goal. Many teams "run their own projects on Twitter", they release some impressive numbers and hope that people will be fooled into thinking that it is an effective system. But we are proud of running a high TPS system for many years. All of this is to increase throughput and reduce transaction costs.

What I want to say is that so far, our system has processed nearly $1 trillion worth of transactions, over 450 million transactions, and issued over 100 million NFTs. No other L2 can achieve these. Our daily TPS is 50% higher than Ethereum, and our weekly TPS is 30% higher than Ethereum, sustained for a whole week. No other system can reach this level, and we have never used more than 1% of Ethereum Gas, even when our TPS has increased by 30%.

BlockBeats: StarkEx is a very specific use case. As a technology-driven project, StarkWare seems to have had a very clear positioning of its business model from the beginning.

Eli: I often like to say "look up at the stars, but keep your feet on the ground." We are very knowledgeable in mathematics, engineering, and technology, and are easily attracted to the next cool scientific project, and like to showcase some trendy new things, which is very tempting for me. But we put aside the cool content that cannot meet the immediate needs of users, and instead we focus very hard on providing users and customers with what they really need. As a scientist, the whole team knows that I feel very sorry for not being able to do things like elliptic curve fast Fourier transform (ECFFT), and many other strange technologies that we know can improve performance by 10 or even 100 times.

StarkWare team members, image source from StarkWare

BlockBeats: Next, I want to talk about the Cairo language. As an Ethereum L2, Starknet is not compatible with Ethereum EVM, and developers must use the Cairo language to build applications. This seems to have lost Starknet many of the advantages of the "EVM-compatible ecosystem". Why choose to build your own language?

Eli: Yes, I want to say a few things about Cairo. First of all, it is an advanced, next-generation smart contract programming language. It supports some new features from the beginning, such as smart wallets, or account abstraction, which are built into the Cairo language. This is a programming language inspired by Rust, and many developers who have tried Solidity and know Rust, especially those who know Rust, say they prefer programming with Cairo rather than Solidity. So it is a very, very good programming language in itself.

The second thing I want to say is that the reason for using a dedicated language to create STARK proofs or general validity proofs is similar to the reason why you want to write smart contracts in Solidity. You need to use Solidity not because it has a better developer experience than Python, Rust, or C++, but because when you move to a new framework with blockchain infrastructure, you have to use a different programming language. Solidity is good because it can be effectively compiled into the Ethereum virtual machine. Here's another example. If you want to write really good graphics using a GPU, you should use CUDA because it is a language that can maximize GPU performance.

STARK proof is the same. With a different virtual machine, there is a set of different constraints on what makes something valid or invalid. If you want to achieve the performance that STARK proof can achieve, such as putting one million NFTs in a block on Ethereum, you must use the programming language more efficiently. We can mint ten million NFTs in a proof on Immutable X, and I can't imagine any EVM-based or zkEVM-based solution coming close to what we can fit in a single blockchain proof. I can challenge all the zkEVMs in the world, and they won't be able to do it. That's why you need a different computing model and a different programming language.

BlockBeats: However, many ecosystem projects that previously used Rust language in Polkadot and other platforms have generally reported issues with operating costs, as hiring or training an engineer who knows how to develop contracts using Rust language is very expensive. On the other hand, if a team develops a project on Ethereum or an L1 compatible with EVM, it is very cheap. What do you think about this situation? Is this a problem for the Starknet ecosystem?

Eli: This may be a problem, but developers are flocking to Cairo and STARK. The number of developers and teams is increasing every day, and I think they see the potential. Many people understand the scalability issue and ask themselves what the best and most forward-looking solution is, and what truly opens up global demand for scalability. I think many of them have come to the right conclusion, which is to take the path of Starknet and Cairo 1.0.

Here is an analogy. Typically, you would use Python to write the first version of your software, but when you want to scale, you need to use other highly efficient languages such as C++, WASM, Rust, etc. I believe the same thing will happen on Cairo. You may deploy Solidity code to Kakarot, but it's like writing a high-frequency trading engine in Python, which is not appropriate. You need to write in another language, and that other language will be Cairo.

BlockBeats: There are now some projects developing zkEVM based on Starknet.

Eli: Yes, there are very good projects being built on ZK-EVMs on StarNet. The first one is called Warp, made by the NetherMine team, which is very excellent. The second one is called Kakarot, which is a forming community.

Kakarot is a ZK-EVM built on top of Cairo. Therefore, I am very certain that most ZK-EVMs will be deployed on Starknet. If you already have the ability to port your Solidity or EVM code to L2, the best way to do so is on Kakarot or Warp. This once again demonstrates the power of Cairo and Starknet.

ZK Rollup's Track Competition and Starknet's Ecological Development

BlockBeats also mentioned the competition between ZK Rollup and the development of Starknet's own ecosystem in the interview. As the most technically demanding field in the entire cryptocurrency industry, it seems difficult for ordinary users to distinguish the advantages and disadvantages between zkSync and Starknet. For most people, the actual situation depends on who is better at "getting things done". From this perspective, StarkWare's concept of being driven by technological innovation seems to have posed a challenge for Starknet. How does Eli himself view the competition between ZK Rollup? What are his expectations for the development of Starknet's ecosystem?

BlockBeats: In the current ZK Rollup track, Starknet and zkSync are absolute leaders, and there seems to be a strong competitive relationship between the two. In your opinion, what is the difference between Starknet and zkSync, and what are the advantages of Starknet?

Eli: You have to ask yourself, where are the best technical steps? Where is the place that is most likely to bring together the most developers and provide the best, most secure technology? We demonstrated our ability before zkSync, they are good at telling stories, but there is a big mismatch between the stories they tell and the experience of developers. I have a suggestion, I encourage developers who are reading this article to try developing or deploying something on zkSync and try developing and deploying something on Starknet, you will feel a distinct difference.

I'll tell you a story. Someone asked on Reddit who could create something that could handle 300,000 transactions. We achieved this on the mainnet with a TPS of approximately 3,000. A week or two later, the zkSync team came out and said they had 3,000 TPS, but it had never been measured, proven, or demonstrated. However, it's a good story. In this industry, there are many people who like to tell stories, and there are also people who demonstrate facts. We are proud of our ability to demonstrate facts.

BlockBeats: Some users have also reported that the gas fees for transferring assets or interacting on ZK Rollup are currently very high. Why is this?

Eli: Currently, due to high demand, Starknet is experiencing congestion. We will release version 12 within the next two weeks, which will greatly increase TPS and address most of the demand. Then, in the next version, when we fully integrate Volition for off-chain data processing, prices will be significantly reduced, which may happen in one or two months.

BlockBeats: When it comes to ecosystem development, some people have indeed expressed that Starknet is more balanced than zkSync.

Eli: That's right, this is the result of a better and deeper technical understanding. We have been working in this field for a long time, deploying content in production environments, and honing our systems. We know what we are doing. But we are not good at telling stories and rarely hype things up. We are like Tesla, which doesn't have a marketing department. Our product is our marketing.

StarkWare Sessions 2023 conference scene, image source from StarkWare

BlockBeats: However, in the Web3 field, teams that understand marketing seem to be more popular. Many technology-driven projects have encountered some problems in their ecological development, haven't they?

Eli: No, I don't think this is what's going to happen next. The reason I think this is because Ethereum has developed in this way. One day, there will be a very successful app that understands the capabilities of Starknet. What that app is, I don't know right now. If you ask me to guess, I don't think it's a product that currently exists on L1 and can be easily copied and pasted onto L2.

So I believe it will make everyone see and talk about it, because this is a brand new application that cannot be achieved on L1 or even other L2. This will be a turning point, and developers will flock to it. That's why we focus most of our attention here. We came to EDCON this time to connect with more developers and invite them to join our ecosystem. Because among them, there will be someone who creates something wonderful that I cannot predict.

BlockBeats: Do you have any directional suggestions for developers who are preparing to develop in the Starknet ecosystem? What can Starknet provide for them?

Eli: I cannot answer this question for them. Even if I provide an answer, they should not listen to me. They should make their own decisions. I believe there are some amazing things that can be done on Starknet, such as building a database infrastructure, advanced Oracle services, Proof of Humanity, social networks, and many other truly amazing things. They should do some research and find out what they think is missing or what they find most interesting.

Starknet is the next step in the evolution of blockchain, and it is a very important one. If you are a developer, Starknet will be ready for users to use, and we are building it for the end user. I think we have a very clear path forward, with more developers and tools to be built, and many things to be done. There are many opportunities for you to stand out and work hard to earn your own reputation.

BlockBeats: Finally, is there anything you would like to say to the readers?

Eli: If there was a time machine, you might wish to go back to the early days of Ethereum, where building almost anything you wanted would be very successful, such as the first prediction market, the first wallet, etc. But the game is not over, there are still opportunities for the next generation, and I believe the winners of this generation will be Starknet. So now, besides having a time machine, everyone can also learn about Starknet. The time is now.

Welcome to join the official BlockBeats community:

Telegram Subscription Group: https://t.me/theblockbeats

Telegram Discussion Group: https://t.me/BlockBeats_App

Official Twitter Account: https://twitter.com/BlockBeatsAsia